Packaging giant Ardagh Group is to consider increasing automation at its US plants on foot of labour difficulties.

The company's chairman Paul Coulson told an event in Dublin yesterday that the company has encountered problems with the labour pool - including drug use, with the country in the grip of an opioid crisis.

"The US is a great market but it has its issues. Its economy is growing so well that it's pretty much, in many places, at full employment. And if you talk to a number of industrialists and people who are manufacturing in particular - it's actually quite difficult," Mr Coulson said.

"The labour pool is difficult. It's difficult to get people who are drug free, etcetera etcetera, and to train people. We're having to put a lot of emphasis and investment into training people and retraining people because it's difficult to get people. Also labour costs in some areas are quite high."

He said high healthcare costs are one of the reasons for that.

Mr Coulson was speaking at an economic conference centred on the relationship between Ireland and the US. Asked about the effect of Donald Trump's tax changes, which are designed to incentivise companies to do more business in the United States rather than in countries like Ireland, Mr Coulson said there was "no doubt it's encouraging people to do things in the US".

He said however that this may contribute to the labour difficulties

"One of the issues with more plants staying at home or being set up, will be where is the labour pool coming from? Because if you've got reduced immigration into the country, I think that's going to become an issue there.

"I think one of the things you'll see, and certainly one of the things we have to look at because of the issue on labour cost and labour availability, is more automation of our plants. That's something we will have to look at."

Crest is moving in to the US for the first time, Ms Cullinan said, because a customer had decided to manufacture in the US rather than in Ireland.

"The customer who's given us the first order of a schedule was going to do that work here in Ireland - they've already got a number of plants here. And now it's become more attractive for them to do it in the US. So that's why we're going in," Ms Cullinan said.

Mr Coulson said businesses looking to enter the market should be aware of differences in the regulatory regime. "I suppose if we had our time again we might have taken a more conservative approach to the anti-trust regulators, when we were acting as a consolidator.

"Regulation there is very different than here. It tends to be more combative and confrontational than what you're used to. It's just the structure of the system and it's something that you need to get your head around. And not just anti-trust regulation but also environmental regulation. The whole lot - it's quite different from Europe in that sense."